EP0037885B1 - Circuit de détection de courant de défaut - Google Patents

Circuit de détection de courant de défaut Download PDF

Info

Publication number
EP0037885B1
EP0037885B1 EP81101077A EP81101077A EP0037885B1 EP 0037885 B1 EP0037885 B1 EP 0037885B1 EP 81101077 A EP81101077 A EP 81101077A EP 81101077 A EP81101077 A EP 81101077A EP 0037885 B1 EP0037885 B1 EP 0037885B1
Authority
EP
European Patent Office
Prior art keywords
voltage
input
gate
during
initialization cycle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP81101077A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0037885A1 (fr
Inventor
Anthony John Rice
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of EP0037885A1 publication Critical patent/EP0037885A1/fr
Application granted granted Critical
Publication of EP0037885B1 publication Critical patent/EP0037885B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/16571—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/006—Calibration or setting of parameters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current

Definitions

  • the present invention relates to a fault current detection circuit, the detection threshold of which is self-adjusting and which consequently is very suitable for protecting machines.
  • a fault condition in the load causes additional current which may be called fault current to be drawn from the supply.
  • This additional current causes short circuits which being additional faults further increase the fault current.
  • a protective device which prevents the fault current from increasing so that it does not reach the limit for which the sum of the load currents and fault is equal to the maximum current that the supply can supply.
  • a circuit breaker is used which trips from a fixed threshold.
  • the detection thresholds can also be set automatically by program as described in the publication IBM Technical Disclosure Bulletin, Vol. 20, No 9, February 1978, page 3589. This possibility can of course only be used in machines comprising microprocessors and also complicates, in such machines, the operating procedures, since it is necessary in addition to all the operations generally necessary, be concerned with the limit values to be chosen, load them into memory, which consequently requires intervention by the installer.
  • the present invention relates to a fault current detection circuit with self-adjusting threshold according to the characterizing part of claim 1.
  • a detection circuit makes it possible to protect machines with evolving configuration.
  • the detection circuit comprises means for generating a first voltage proportional to the current supplied by the power supply and means which operate during an initialization period to generate a second voltage equal to the initial value of the first voltage and derive from this second voltage a threshold voltage which will be used as the current detection threshold during operation.
  • a detection circuit with fixed threshold which operates with a reference voltage.
  • the detection threshold is adjusted at the end of the initialization period as a function of the load to be supplied and consequently it adapts to each configuration of the machine.
  • FIG. 1 very schematically illustrates the problem to be solved by the circuit of the present invention.
  • a power supply 1 delivering a fixed voltage supplies an IS current to a payload, which can be constituted by all or part of a machine.
  • the load is represented by a resistor RL which draws a load current IL.
  • IF load current
  • an additional fault current diagrammed by IF in the figure is taken from food. The heat dissipated as a result of this additional current can cause failure conditions which will further increase this IF current, until IS being the maximum current which the supply can supply.
  • the charging current can vary between 20 and 80 Amps. Consequently, if the power supply can provide a maximum output current of 100 Amps, the trigger current must be set to 100 Amps accordingly depending on the load, the IF current will vary between 20 Amps and 80 Amps.
  • the circuit shown in Figure 2 ensures adequate protection regardless of the configuration of the machine.
  • the circuit allows automatic initialization of the detection threshold, each time the machine is powered up.
  • FIG 2 there is shown schematically the power supply 1, and the variable load RL, which are the elements of Figure 1.
  • the detection circuit according to the present invention generates a control signal on line 3 to stop the power supply in the event that a fault condition is detected which causes the machine to stop.
  • a resistor RS is placed in the supply circuit and a differential amplifier 4 is placed at the terminals of this resistor to provide at its output a voltage VS proportional to the current IS, without modifying this current significantly.
  • This voltage VS is applied to the three + inputs, of three comparators 5.
  • a logic circuit comprising an AND gate 8, a counter 9, a digital / analog converter 10, supplies the input of the converter 10 with the input to comparator 6.
  • a bridge of resistors R1, R2 is connected between the output of converter 10, and ground, the common point of resistors R1 and R2 constitutes the input - of comparator 5.
  • the AND circuit 8 has three inputs, a first input 11, receives an initialization signal, a second input 12 receives a clock signal, and the third input 13 is connected to the output of the comparator 5.
  • the output of the circuit 8 supplies the control signal to the counter 9.
  • the counter 9 is reset to zero by a signal on line 14.
  • the output bus 15 of the counter is connected to the inputs of the digital / analog converter 10.
  • the comparator 7 receives on its input -, a reference voltage VR which is supplied by a generator 16. This reference voltage VR is also used by the converter 10.
  • An AND gate 17 receives on one of its inputs the output of comparator 6, and on its other input the initialization signal inverted by the inverter 18.
  • the output of AND gate 17 is connected to an input of OR gate 19 the other input of which is connected to the output of the comparator 7.
  • the output of the OR gate 19 provides the control signal on line 3 which cuts the supply when a fault condition is detected.
  • the operation of the detection device is as follows.
  • the current IS and consequently the voltage VS will gradually increase to settle at the nominal value which depends on the machine configuration, shown diagrammatically by the load RL.
  • This voltage VS is shown diagrammatically in FIG. 3.
  • the voltage VS is stabilized after a time TD, which corresponds to the initialization period.
  • the content of the counter is equal to zero, since it had been reset to zero when the machine stopped, consequently the output of the converter 10 is equal to zero, of this fact the voltages VD and VC at the inputs - comparators are zero.
  • comparators 5 and 6 detect this condition.
  • the comparator 5 therefore supplies a counting control signal on line 13.
  • the signal on line 11, being at the high level, the gate 8 is conditioned and lets the clock pulses which are applied to the counter 9 which starts to pass. count.
  • the voltage VC will be equal to VS at the end of the initialization period so that the output of the comparator 5 becomes zero and the AND gate 8 no longer lets the clock signals pass.
  • the content of counter 9 is frozen so that VC remains fixed at the initial value of VS, and the charging current is memorized.
  • the AND gate 17 is conditioned by the fact that the inverter provides a high logic level. Consequently, when the voltage VS becomes greater than the threshold voltage VD, ie 1.2 VS, as a result of a fault in the machine, the AND gate 17 detects this condition and the power supply control command signal is transmitted by OR gate 19.
  • the threshold voltage which is always equal to 1.2 VS, is self-adjusting according to the charging current.
  • a fixed threshold VR is used which is supplied by the generator.
  • the comparator 7 provides a signal which is transmitted by the OR gate 19 on the line 3 to cause the supply to stop.
  • the graph in FIG. 4 allows a comparison to be made between the protections provided by the device of the present invention and a detection device with fixed threshold as described with reference to FIG. 1.
  • the fault current IF is represented by function of the load current IL in both cases, fixed threshold detector curve A, and variable threshold detector of the present invention, curve B.
  • the fault current IF varies between 80 amperes and 20 Amps, while for the variable threshold detector of the present invention, it varies between 4 and 16 Amps.
  • the device of the present invention ensures a protection for all values of the IL load current between 20 and 80 Amps, unlike the fixed threshold detection device.
  • the elements of the circuit of FIG. 2 are conventional elements that can be easily integrated, so the detector can be made in the form of integrated circuits and thus obtain a device which is very efficient and which takes up very little space.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Measurement Of Current Or Voltage (AREA)
EP81101077A 1980-04-10 1981-02-16 Circuit de détection de courant de défaut Expired EP0037885B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8008341A FR2485284A1 (fr) 1980-04-10 1980-04-10 Circuit de detection de courant de defaut
FR8008341 1980-04-10

Publications (2)

Publication Number Publication Date
EP0037885A1 EP0037885A1 (fr) 1981-10-21
EP0037885B1 true EP0037885B1 (fr) 1984-07-25

Family

ID=9240842

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81101077A Expired EP0037885B1 (fr) 1980-04-10 1981-02-16 Circuit de détection de courant de défaut

Country Status (6)

Country Link
US (1) US4375072A (enrdf_load_stackoverflow)
EP (1) EP0037885B1 (enrdf_load_stackoverflow)
JP (1) JPS56154672A (enrdf_load_stackoverflow)
CA (1) CA1165396A (enrdf_load_stackoverflow)
DE (1) DE3164945D1 (enrdf_load_stackoverflow)
FR (1) FR2485284A1 (enrdf_load_stackoverflow)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2123627A (en) * 1982-04-08 1984-02-01 David Alan Dolbey Jones Electrical circuit interruption
US4625283A (en) * 1982-05-07 1986-11-25 Cooper Industries, Inc. Method and apparatus for digitally measuring alternating current
US4677581A (en) * 1985-05-30 1987-06-30 Allied Corporation Multichannel, self-calibrating, analog input/output apparatus for generating and measuring DC stimuli
EP0211507A1 (en) * 1985-07-26 1987-02-25 Tektronix, Inc. Load-dependent current limiter for the power supply of a multi-module electronia system
US4720758A (en) * 1985-07-26 1988-01-19 Tektronix, Inc. Load dependent current limiter for the power supply of a multi-module electronic system
US4713553A (en) * 1985-10-21 1987-12-15 Motorola Inc. Fast power-fail detector for power supplies with energy hysteresis
US4796142A (en) * 1986-10-16 1989-01-03 Square D Company Overload protection apparatus for emulating the response of a thermal overload
IT1219951B (it) * 1988-05-31 1990-05-24 Giancarlo Sacerdoti Dispositivo di sicurezza per la rilevazione della corrente di terra e spina elettrica di sicurezza dotata di tale dispositivo
EP0370139B1 (en) * 1988-11-22 1993-09-15 Mitsubishi Denki Kabushiki Kaisha Circuit breaker with overcurrent protection
DE3841186A1 (de) * 1988-12-07 1990-06-13 Asea Brown Boveri Einrichtung fuer elektrische verbraucher
US5272585A (en) * 1991-06-27 1993-12-21 Gibbs John H System to prevent electrical shorts by a microprocessor breaker box
US5506789A (en) * 1993-10-15 1996-04-09 The Texas A & M University System Load extraction fault detection system
JP3233557B2 (ja) * 1995-07-21 2001-11-26 シャープ株式会社 半導体集積回路の閾値特性測定方法および装置
CN101661055B (zh) * 2008-08-27 2011-07-13 中兴通讯股份有限公司 一种有源电路电流告警的方法及装置
EP2241344B1 (en) * 2009-04-16 2013-12-11 F. Hoffmann-La Roche AG Ambulatory infusion device with sensor testing unit
EP2282175A3 (en) * 2009-08-06 2011-10-19 Yokogawa Electric Corporation Measurement apparatus
CN102074928B (zh) * 2009-11-20 2015-01-14 北京普源精电科技有限公司 一种恒压恒流电源及其过压、过流保护的自校准方法
CN102681531B (zh) * 2012-05-10 2014-02-05 四川金网通电子科技有限公司 一种实现电机控制器限流电流值自校准的方法

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3626262A (en) * 1969-08-22 1971-12-07 Gen Electric No-load torque compensation system and the application thereof in adaptive control
US3979255A (en) * 1973-09-04 1976-09-07 Combustion Engineering, Inc. Method for operating a system with a variable excursion margin setpoint
US4012669A (en) * 1975-08-29 1977-03-15 Envirotech Corporation Electronic overload detecting device
US4208625A (en) * 1976-02-23 1980-06-17 Micro Sensors, Inc. Capacitive measuring system with automatic calibration
DE2609654B2 (de) * 1976-03-09 1978-01-05 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Digitaler ueberstromausloeser
US4160282A (en) * 1977-10-03 1979-07-03 Consolidation Coal Company Overcurrent protection apparatus

Also Published As

Publication number Publication date
EP0037885A1 (fr) 1981-10-21
FR2485284A1 (fr) 1981-12-24
US4375072A (en) 1983-02-22
JPH05666B2 (enrdf_load_stackoverflow) 1993-01-06
JPS56154672A (en) 1981-11-30
CA1165396A (en) 1984-04-10
DE3164945D1 (en) 1984-08-30

Similar Documents

Publication Publication Date Title
EP0037885B1 (fr) Circuit de détection de courant de défaut
EP0190961B1 (fr) Alimentation en courant continu à point de fonctionnement ajustable
EP0133128B1 (fr) Dispositif de protection à surintensité de courant
EP0110775B1 (fr) Régulateur à faible tension de déchet
EP0396477B1 (fr) Déclencheur statique pour un disjoncteur de protection d'un réseau triphase, permettant la détection du type de défaut
EP0014757A1 (fr) Circuit détecteur de défauts survenant sur une ligne d'alimentation
EP0240434B1 (fr) Circuit de protection d'alimentation à découpage
FR2466891A1 (fr) Dispositif de protection contre les defauts de mise en court-circuit interne intempestive pour un onduleur a transistors de source de tension
EP3297118B1 (fr) Procédé et système de gestion de la tension d'alimentation d'un dispositif source usb type c
EP0462023A1 (fr) Commutateur statique
FR2535870A1 (fr) Circuit d'alimentation en courant electrique d'un micro-ordinateur
EP0002983A1 (fr) Circuit de commande de puissance et alimentation à découpage l'utilisant
FR2942352B1 (fr) Identification et protection d'un systeme de courant c.a-c.c aerospatial en presence de contenu de courant c.c en raison des charges defectueuses
FR2484740A1 (fr) Circuit de protection pour un transistor de commutation et son procede de realisation
FR2720559A1 (fr) Dispositif de synchronisation pour un système d'alimentation sécurisé.
CH634182A5 (fr) Circuit de commande de grille pour convertisseur a thyristors.
EP0177373B1 (fr) Dispositif pour arrêter le déroulement des programmes en cours d'exécution dans un microprocesseur préalablement à la disparition de la tension d'alimentation du microprocesseur
WO2020038918A1 (fr) Systeme de detection d'une baisse de tension d'une alimentation alternative
EP0539301B1 (fr) Dispositif de couplage d'une source extérieure d'alimentation en énergie électrique à un avion au sol
EP0626744B1 (fr) Dispositif de limitation de courant du type placé entre une carte électronique et des moyens d'alimentation
FR2720558A1 (fr) Système d'alimentation sécurisé.
FR2857111A1 (fr) Microcontroleur a protection logique contre les decharges electrostatiques
EP0488882B1 (fr) Dispositif régulateur de la tension de charge d'une batterie délivrée par un alternateur
EP0055661B1 (fr) Dispositif de commande des moyens de régulation dans un convertisseur électrique alternatif continu, de forte puissance
EP0536011A1 (fr) Dispositif de commande et de protection de sorties, notamment pour automate programmable

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19811119

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB IT

REF Corresponds to:

Ref document number: 3164945

Country of ref document: DE

Date of ref document: 19840830

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19920113

Year of fee payment: 12

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19920729

Year of fee payment: 12

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19930216

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19930216

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19931103

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950128

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19961031

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST